modrinth-mcp

modrinth_search_projects

Read-only

Search Modrinth for Minecraft mods, plugins, and more using text queries and optional filters. Returns key project details like title, type, downloads, and description.

Instructions

Search public Modrinth projects. Returns a compact list of hits (slug, title, project_type, downloads, description).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "query": "<query>"
    },
    "name": "modrinth_search_projects"
  }
}

Input Schema

Name	Required	Description
`limit`	No	Max hits.
`query`	Yes	Search text, e.g. 'sodium' or 'anvil'.
`facets`	No	Optional raw Modrinth facets JSON, e.g. '[["project_type:mod"],["categories:fabric"]]'.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 22, 2026

TDQS

A4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond annotations: it constrains the scope to public projects, promises a compact hit list, and enumerates returned fields (slug, title, project_type, downloads, description). This is useful given no output schema exists.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, front-loaded sentence that states the verb and resource first, then summarizes the return shape. Every word contributes value, with no filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only search tool with good annotations and full schema coverage, the description is mostly complete: it identifies scope, result compactness, and fields. It doesn't mention default limits or facet behavior in detail, but those are already addressed by parameter descriptions, so the gap is minor.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and each parameter (query, limit, facets) has a meaningful description. The tool description adds no extra parameter semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description uses a specific verb ('Search') and clearly identifies the resource ('public Modrinth projects'), which distinguishes it from sibling tools like get_project or list_project_versions. It also states the result shape, making the tool's function immediately clear.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies when to use the tool by naming 'Search,' but it does not explicitly contrast it with alternatives or state when not to use it. For example, it doesn't mention that get_project would be preferable for retrieving a known project's full details.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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